


Coevolution

by OneOfThoseThings



Series: Interspecies Compatibility [10]
Category: Doctor Who (2005)
Genre: Alien/Human Relationships, Angst and Fluff and Smut, Canonical Assault, F/M, Hurt/Comfort, Mind Control Aftermath & Recovery, Post-Episode: s04e10 Midnight, Reckless Tone Shifts Between Chapters, Straight up sex, Telepathic Sex, Telepathy, Whatever warnings apply to Midnight apply to this fic, no beta we die like men
Language: English
Status: Completed
Published: 2020-03-14
Updated: 2020-03-14
Packaged: 2021-02-28 21:09:01
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 4,522
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23143693
Author URL: https://archiveofourown.org/users/OneOfThoseThings/pseuds/OneOfThoseThings
Summary: In the aftermath of the events on Midnight, Donna tries to be supportive. She's not quite sure how to be supportive for this sort of thing, so she tries several methods. The Doctor appreciates some of those methods more than others.
Relationships: Tenth Doctor/Donna Noble
Series: Interspecies Compatibility [10]
Series URL: https://archiveofourown.org/series/1637608
Comments: 16
Kudos: 131





	1. Part the First

**Author's Note:**

> Coevolution (ala Wikipedia): Occurs when two or more species reciprocally affect each other's evolution through the process of natural selection

Without quite remembering the steps he took to get there, the Doctor found himself back in the TARDIS. 

He could still feel traces of the entity in his mind, the vague impressions where the frigid tentacles had been ripped out. 

“All right,” Donna said, a bit too loudly, “Looks like we’re adding ‘spas’ and ‘busses’ to the list of things you can’t use safely.” She hovered in his periphery, worrying a loose thread on her sleeve. 

The Doctor walked around the console, touching dials vaguely related to the dematerialization sequence. The TARDIS rumbled and made up the difference. 

“Well, at least we’ve learned something,” Donna continued, like they were having a completely normal conversation that he just happened to not be participating in verbally. 

There was a steady background of white noise, crackling between his ears. His limbs tingled like he’d touched a live wire. He flipped a few more switches and started toward the corridor as the TARDIS dematerialized with a lurch. 

Donna stumbled and righted herself. “Do you want some tea? Maybe a few biscuits? We never did make it to that anti-gravity restaurant.” 

“I’m going to my room,” he said, already halfway through the door. 

“Right,” Donna said, as the door snicked closed. 

His room was silent and empty and for just a moment it was deafening. He cautiously probed his own mind, searching for something he hoped he wouldn’t find. 

Donna burst in, interrupting, “It’s just that I think you should probably eat something. Or drink something. Or take a nice bath? What would make you feel better?”

‘A time machine,’ he thought, ironically, sitting on his bed and tugging at his tie. 

Donna carried on having both halves of the conversation. “Do you want to rest? You don’t normally sleep this much. Do you want to talk? You haven’t really said that much. Is it because you’re tired? You shouldn’t be tired. Are you sure you’re not hungry?” His bedside drawer clicked open, producing a bowl with what was most likely soup judging by the scent. “Oh, perfect! What do you say to a nice―“ She walked around to the side table, putting her hand on his shoulder as she passed and he couldn’t help flinching away. “Sorry!” she yelped, shoving both hands under her own arms. 

He opened his mouth, realized he didn’t really have anything productive to say, and closed it again. 

“Er...” Donna eyed the drawer, arms still clenched around herself. “Right. You probably don’t want me feeding you.” She stepped back, looking around the space. 

He could feel the shadows of bruises forming under his skin where he’d been dragged. If he focused, he could count the fingers― estimate which ones belonged to which human by the span.

“Do you think you could tell me what happened?” Donna asked. “You said there was a… a mental presence… right? But it seems like… Did it… Did it get one of the people to grab you?” 

The mark that would form on his trapezius would match Biff’s hand. The bruise on his ankle was more delicate― most likely Jethro. 

He sighed, deep and weary. “No, they didn’t need any convincing. Just interacting with me was enough.” 

He could smell the bus on himself. The acrid scent of human fear was embedded in the fibers of his suit, woven in with the pinstripes. 

He got up, unbuttoning his jacket. He needed a shower. 

“What do you mean they didn’t need any― Why are you taking your clothes off? Are you― Is this― Are you sure you’re in the right headspace for― Oh, do you want a bath after all?” Donna followed him into his bathroom. 

He shucked off his clothes, heading straight for the shower. The TARDIS twittered, trying to run a diagnostic, but found his barriers up. He twisted the taps manually, and ducked under the spray.

“Um...” Donna shifted from one foot to the other and back. “Do you want me to come in there or stay out here or…? Is there a third option?”

“I’m fine,” he said, lathering on the harshest disinfectant soap he could reach. 

“Right,” Donna said. “No, you seem great. Don’t know what I’m on about.” She grumbled, but moved back to lean against the counter. “What were you saying about the other passengers? Was the thing controlling them as well?”

He scrubbed shampoo into his hair and moved under the overhead waterfall. 

Donna disappeared into his room for the second and third repeat. When he started up a fourth time, she reappeared and calmly suggested, “I think you might be done in there.” 

He completed the fourth circuit, but didn’t start over. She handed him a towel and he dried himself off with a few precise swipes. 

His clothes were gone and some striped pajamas were on the bed. He pulled those on and lay down, for lack of anything better to do. 

He could feel Donna hovering and tried to remember the last question she’d asked. “…The entity took over one of the humans, Sky, but it left the others alone,” he said, affecting a tone like he was relaying a story about someone else. “They decided to throw me out all on their own. Well… as a group, really.” 

“What?!” Donna exclaimed, leaning over, but not touching. “The other passengers tried to― Oh my God! They could have killed you!”

He made a dull sound that was supposed to be a laugh. “I think that was the idea, yes.” 

“Oh my God!” she climbed onto the bed and reached for him, but stopped short when he flinched again. “I’m so sorry,” she said miserably.

He turned on his side. “Not your fault.” 

For some reason she looked even closer to tears at that. “I should have come with you!” Her voice cracked a little on the last word and he found himself reaching for her automatically. 

She burrowed in immediately, wrapping around him like a fist. 

He tensed and flinched as one of her hands crept under his arm where another, larger hand had caught him. 

Donna recoiled, pulling her arms in to her chest. “Sorry!” she said, then, “Hang on―“ She twisted around so she was facing away with her back to him. “Is this better?” 

It was. Surprisingly, it was much better. He put his own arms around her, pulling her back against himself, probably too tightly, but she didn’t seem to mind. She put her arms over his and burrowed back. 

He took a deep breath in and sighed it out, focusing on the feeling of her single heartbeat thudding between his chest and forearm. 

“Would it help to talk about it?” Donna asked after twenty-three minutes and thirty-eight seconds. Her ribcage expanded and contracted with a deep breath. “That’s what they say to do, right? Talk it out?” 

He didn’t think anything could help, but he wasn’t exactly too busy with other ideas to try. “…It got in my head. The entity. I didn’t notice it until it was too far in. I had a subroute open for the TARDIS. Not used to keeping up my mental barriers now that…” Her hair was tickling his nose and he reached up to smooth it down. Donna went very tense against his chest. 

He froze, hand hovering over the side of her head. “Your hair, it’s in my― I was just going to smooth it down…”

“Oh,” Donna squeaked. She hastily straightened her hair herself, the back of her hand brushing his fingers. “Sorry,” she said, again, sounding guilty. 

“It’s okay.” He waited until she resettled and put his arm back, more gingerly. She gripped it to her chest just as hard, if not harder than before. 

“I’m sorry,” she said for what seemed like the millionth time. 

He suddenly couldn’t let it go. “I wouldn’t― For telepathic species, there are strict social codes around engaging in synthesis. Doing so without permission is… the equivalent of assault. I wouldn’t ever―“

“No, I know. I _do_ know, I just―“ Donna cut off, and her heart leapt erratically against his arm. “Wait, you just said that thing―“ She wrenched her head around to look at him, horrified. He could only watch as the puzzle pieces snapped into place. 

“Doctor, I’m so sorry!” She pressed her cheek to his and leaned into him, clutching his arms into her own chest in a strange backward hug. 

He rubbed one thumb over her knuckles, and held her closer than he should. 


	2. Part the Second

After three days, Donna lost all semblance of patience with the Doctor’s continued insistence on TARDIS maintenance. She made it two more days before she decided to force the issue. 

“I have a question,” Donna announced, clanking across the console room grating. 

The Doctor started, dropping a wrench on himself and banging his knee into the underside of the panel he was embedded in. “Oh?” he gritted out, curt and defensive, “Time sensitive is it, this question? Can’t possibly wait until I’m done with repairs?” 

“The mysteriously vague, all-consuming repairs that have never been mentioned before now and don’t seem to have any specific purpose or end? No, I’m pretty sure those could outlast one of our lifespans.” Donna grabbed his ankle, felt him flinch, and switched her grip to the panel instead, trying to drag it off and making an ungodly metal screech.“A little help?” she grunted.

The TARDIS lurched under him, panels grinding, and deposited him back above deck with a disorientating flip that sent several tools clattering. 

“Oh, good, there we go!” Donna stooped down, offered a hand, and hoisted him upright. She let go as soon as he was up, clasping her hands behind her back like she’d taken to doing lately. 

“Well?” He rubbed pointedly at the joint where the wrench had clipped him. “I’m all ears, apparently.” 

“Before I tell you, I have to remind you that you have to tell me if it’s a bad idea. I’m offering because I think it’ll help, but if it’s not going to help, I want you to just say.” 

He narrowed his eyes. “Is this one of those times where you want me to say something just so you can ignore me and do whatever you were going to do anyway? Because I really didn’t need to be up here for that.” 

“No,” Donna said, suddenly uncharacteristically serious. “I need you to be clear. Yes or no― that’s it. You don’t have to explain or qualify― just tell me whether or not you think it’ll help.”

He narrowed his eyes further. “What are you on about?” 

She held up an authoritative finger and then asked, “Would you like to connect again? Mentally? With me? I think I could―“

He cut her off, shaking his head. “You don’t need to offer― I know you’ve been…wary… of it, and I appreciate the gesture, but―“ 

“That’s not what I asked,” she interrupted him. “I asked if it might help. If a person gets… assaulted… some people want to get back into it on their own terms― it’s a personal choice, right? I need you to tell me what would help here. I can’t guess.” 

“Donna,” he said, very slowly. “I’m not going to ask you to do anything you don’t want to. No matter how well-meaning you are.” 

“I’d be fine with it,” she said, then lifted her chin higher and added, “I’d like to try it again. If it’d help. I won’t lie and say that’s not a factor, but I’m not offering something I’m not comfortable with.” 

The Doctor absolutely wanted that connection. He wanted it so much, he could feel it clenching in his throat and knotting in his stomach. But the thought of taking it at any expense made those same reactions twist into something sickening and dark. 

“I can’t ask you to do that,” he said. 

She sighed, looking older than she had any right to. “I think I could feel it,” she said, voice lowered ominously. “The last time. It was― I wasn’t expecting it, you know? And it was― I don’t think I have the right senses to even describe it. And you’re― I know we’re not the same. I _know_ that! I knew _that_! But I know how big the ocean is too, and it’s just so easy not to think about it… So it was like getting swept off the edge of a reef and suddenly finding myself in open waters― everything just went on and on, with no end in sight and it was all so…” She looked at him with something far deeper than pity. “It was so empty... so lonely.”

He swallowed around the boa constrictor in his throat. “Yes, well, as I said, you don’t have to―“ 

“No,” she cut him off, “I’ve been lonely before. But you― that― it’s more than loneliness; it’s _knowing_ that you’re the last, that there’s no one waiting. And it’s― it’s―“ She choked up a bit, but swallowed. “I’ve never felt anything like that before.”

He stared at her, feeling the emptiness she’d shied away from welling in his chest where it always waited, just beneath the surface. “You don’t have to do that again. I shouldn’t have―“

“But you could feel _me_ there, right? I know I’m just some goby and you’re used to a sea full of blue whales, but it felt like you could…” she trailed off, gesturing. 

“Of course I could feel you,” the Doctor said, “You’re not _just_ anything, Donna Noble.” A phrase echoed back to him, something he was going to say. “You’re the most important woman in the whole wide universe.” For some reason, it made him feel terribly sad. 

Donna scoffed, “You don’t have to lay it on so thick; I’m already offering.” She held out her hand. 

He couldn’t quite keep himself from taking it. 


	3. Part the Third

“Okay, how should we do this?” Donna asked like they were trading snacks in the schoolyard. 

“I’m still not entirely sure we _should_ do this…” the Doctor pointed out. 

Donna stopped short, her grip loosening. “But you want to… right?” 

He should say no. She was only offering out of some misplaced sense of loyalty. But when she looked at him over her shoulder he couldn’t quite form the lie. 

“Yes,” he said. 

She pushed the nearest door open and his room appeared behind it. 

With a shrug, Donna headed for the bed, toed off her shoes and sat cross-legged and slightly off-center. At her expectant look, he followed suit, sitting close enough for their knees to touch. 

She put her hands up, waiting for him to mirror her, but he hesitated. “Are you sure?” 

She gave him an impressively scornful look, but only replied with a single, well-enunciated, “Yes.” 

He took a deep breath and leaned forward. “Then we might as well do it properly.” He ducked his head, aligning their temples on the right side, raising his right hand to hover beside her other contact point. 

Donna mirrored his position. “Like this?” 

He nodded, suddenly having a little trouble keeping his breathing even. “You _are_ sure?”

Instead of answering, Donna closed the gaps between them, establishing proper contact. 

~*~

Fully aligned, the Doctor’s mind overlaid Donna’s, like panes of glass held at angles― a kaleidoscope of mirrors reflecting eleven dimensions instead of three. 

Her lightning thoughts knotted in on themselves, trying to clamp closed before they could unravel. 

“It’s okay,” he said, and Donna startled, feeling the reassurance in her mind as clearly as hearing his voice in her ear. “It doesn’t work like that. You won’t lose yourself. You can let go.” 

He carefully shored up the outline of his own mind, making the points of reflection clearer and tilting the kaleidoscope just enough to show that it was a multidimensional echo chamber, not a black hole. 

Donna relaxed her grip, glowing like the inside of a plasma globe. The recursive planes of a Time Lord consciousness provided no resistance, allowing the plasma to swell unchecked, forming fractals, but never diminishing. 

“Just like that,” he said as much as thought. 

A sparkling, fruity taste danced on his tongue. He could feel her expanding, testing for limits that she wouldn’t find. Every point of contact sang with curious glee and colored the landscape in bright spatters of sensation. 

~*~

Some unclear amount of time later, Donna took a great, gasping breath, and he opened his eyes when it caught like a sob. 

“Donna,” he managed, sounding scratchy and hoarse. Not enough oxygen. He pulled in more. “Are you―“ 

“I’m fine!” Donna said, pulling back. Her features swam into focus, and her eyes were wet, but she was also smiling like she’d just seen something _marvelous_. “That was…I don’t even know the word!”

And suddenly she was hugging him, all warm and soft and real and some tense band of unease loosened so suddenly his head just dropped to her shoulder. 

She tensed. “Are you― Was that all right?” 

“Oh, yes,” he breathed, and Donna immediately relaxed. 

“Feeling a bit better, are we?” Her tone was light, but she gripped spasmodically at his scapula. 

“Oh, yes,” he said, but that time it came out a bit damp. 

Donna hummed, pleased. “See, this is why you should always listen to me. Acting like you’re all alone when I’m right here,” she tutted and petted his head where it was still on her shoulder. 

Something terribly dangerous burned between his hearts, and he couldn’t quite bring himself to let go so he just held her tighter and then a bit tighter still. 


	4. Part the Fourth (NSFW)

The Doctor felt distinctly better. The vague cottony feeling had left his head and he'd stopped feeling uncomfortably cold. It probably helped that Donna was asleep on his arm, radiating heat.

He couldn’t remember any other human sleeping this much. He was beginning to suspect that there was something wrong with her. And he had plenty of time to think it through, lying around with a snoring human pinning him in place. 

She snuffled, like she’d heard him even _thinking_ about her snoring, and he held very still until she shoved herself over onto her side and settled into a lighter, wheezing cadence. 

He waited, but she didn’t wake up and start one of her rants so he figured he was safe for the moment. 

Just in case, he worked the blanket out from under himself and folded it over her, leaving his hand on her shoulder because it seemed like more trouble to figure out another place to put it. It was possibly not conducive to maintaining heat, but she’d never begrudged him his lower body temperature before. 

Point in case, she fumbled around sleepily, catching his hand and dragging it under her as she rolled onto her stomach, pulling him half on top of her. 

“Five more minutes, and I’ll rock your world,” she mumbled, nearly completely muffled by the pillow.

“…Donna?” He blinked at the back of her head. 

Snickering, she wriggled her right hand out, groped around until she located his elbow, and unceremoniously yanked that arm under herself as well. 

“Donna!” he groused and got a mouthful of hair for his troubles. 

She pulled his arms in tighter and hummed, contentedly, “For someone as skinny as you are, you make a decent big spoon.” 

“Such high praise,” he said, but Donna was sleep warm and relatively placid, and it was usually easier to let her do what she wanted anyway. He gingerly tried to relax and she rubbed her thumb over his wrist where it was still trapped between her and the mattress. 

She shifted a bit, stretching, like her body was coming back online one muscle group at a time. Her hips circled in a slow figure eight, paused, and then repeated. 

His body, which was well on its way to a Pavlovian response, followed the movement with interest. 

“I knew you were lying about being asexual,” she muttered, “You lie about the strangest things.” 

He sniffed, “I’ve already told you, it’s a functional definition not an orientation. You’re just bad at listening.”

“Hmm? What was that?” she asked, arching her back.

“…Not that it matters to _me_ , but if _you_ happened to have an interest in a human-style round, I might be willing to oblige,” he offered, magnanimously. "I know it's been awhile. Ages, by human standards." 

“Kind of you to offer,” Donna said and arched again, “But I wouldn’t want to put you out.” 

“Wellllll,” he drawled, “I might not _mind_ , per se.” 

There was a brief, appraising pause, and then she let go of his arms. When he propped himself up, she immediately turned her head to look at him as best she could through her somewhat tangled hair. 

“Want to try a combo round?” she asked. 

“What?” he frowned, wondering if she was still more asleep than he’d thought. 

She huffed, trying to dispel the hair in her face with limited success. “Want to see if we can connect,” she angled her head meaningfully, “while connecting?” she wriggled her hips and arched her brow. 

He meant to make a clever remark about her one-track mind or possibly addictive personality disorder, but the wires got crossed and instead he flipped her over and pressed his mouth to her mouth. 

He blamed her overly-aggressive classical conditioning. And boredom, from lying around so much lately. 

Donna squeaked and laughed, but she also kissed him back with interest, wiggling around to face him properly. 

Her hands went straight to his collar, but she pulled back to look at it. “You’re still wearing your tie?” 

He looked down at it and back up at her. “Why would I have taken it off?” 

She snorted and muttered something that sounded like “barmy alien,” but resumed pulling it loose and then set in on his buttons. 

There was an awkward tangle of limbs and fabric, but they managed to get down to skin without any loss of extremities and it was hard to worry about a few misplaced elbows and knees with Donna pressing closer and then closer still. 

Having been quite successfully conditioned to associate this lead-up with sensations he was very interested in repeating, the Doctor’s body responded immediately. Donna’s pheromone levels spiked and his nerve endings pricked up in response. Little encouraging noises started up in the back of his throat, and Donna responded in counterpart, rubbing at the base of his neck like she was going to follow the sounds straight to the source. 

“Can I put my arms around you?” she asked, and he nodded, but his mouth was on the soft skin just over her left breast and she eventually had to shove him back to manage it. 

Donna herded him into a seated position and climbed into his lap, arranging them in a much closer version of their position the day before. His stomach clenched and his throat constricted.

“Think this’ll work?” she asked. 

“Yeah,” he said, sounding choked and embarrassingly eager, but Donna’s pulse jumped against him and she slid down with a few embarrassing sounds of her own. 

She crossed her legs behind him and sank down. Her muscles clenched like she was trying to swallow him and he kissed her just to muffle his groans. 

Donna began a rocking motion and when he bent his knees her belly rubbed against him hard enough for him to feel the underlying muscles contracting. 

She broke off the kiss, pulling back to look at him with pupils blown wide and unfocused. Two fingers brushed over his right sideburn. “Want to―?”

His right hand was already at her temple, pressing her other to his. 

~*~

The first moment of contact was electrifying and disorientating beyond anything the Doctor had ever experienced. 

Her lightning storm raged and his kaleidoscope spun wildly and it all caught together like sensory overload. But the madness had a center, and when the Doctor focused there, he could see the magnetic field lines guiding the chaos. 

He angled his hips, startling Donna into releasing her grip, and pulled her focus into place. 

Her instinctive panic flipped to wonder as the eye of the storm revealed intricate patterns that could rival the formation of a planet. 

Plasma arched in endless fractals and every sensation overlapped. Her reactions sparked bright incongruous colors that pricked his tongue and flashed behind his eyes. 

He could feel her moving against him and feel her feeling him feeling her, and it should have been maddening, but it was marvelous. 

Something brilliant welled up and it was impossible to tell where it started or ended, but it echoed between them in increasing urgency until it whited out his receptors. 


	5. Part the Fifth

After disappearing for yet another shower, the Doctor found Donna in the console room, staring up at the central column like she’d only just then noticed it. 

The TARDIS sang curiously, brushing soothing tendrils over her consciousness at a frequency too low for humans to detect, and Donna shivered. 

He didn’t make a sound, he was sure of it, but she startled and turned like he’d started up a mariachi band.

“So where to next?” she asked. “I can hardly remember the last face I saw that wasn’t yours.”

He looked her up and down, but her mouth quirked. Probably joking. 

She cleared her throat, eyebrows climbing, and he remembered she’d asked a question. 

“Right!” he said, making his way to the console, “Up for a spin on the random setting?” 

She crossed her arms, leaning over his shoulder to look at the screen she had absolutely no hope of reading. “I thought we were going to get breakfast. Or lunch. Or whatever. Can you get her to do random, with a caveat that there should be food available?” 

“Adding parameters to the random setting sort of takes the point out of the random setting, don’t you think?” The fact that he had no idea whether or not he could add parameters had nothing to do with the validity of that point. 

Donna rolled her eyes. “Fine. Just pick somewhere with a market first.” 

He grumbled about picky humans, clicking through sub-screens. In his periphery, Donna resumed staring at the central column. 

The navigation screen flickered and brought up coordinates. “Oh, this could work…” the Doctor said, stroking two fingers over the coral. 

The TARDIS hummed and Donna tilted her head like she was listening for something just out of her range of hearing. 

“How would you like to see a planet that’s basically one big market?” he asked. “There’s this local drink― best foam for centuries!” 

She nodded, then actually heard him, and nodded harder. “Sounds perfect!”

He set to flipping switches and twisting dials and tried not to notice Donna flicking glances at his spare hand under the console. He hopped around, subtly nudging the hand further out of view with one foot, and she looked away. 

The Doctor held out the hand that was actually attached to him and she took it without hesitation, letting him pull her to the doors. 

He grinned at her, already anticipating her reaction, “Donna Noble, welcome to Shan Shen.” 


End file.
